Ernest and Evelyn Rady are doubling down on their quest to help change the lives of children.

Eight years after donating $60 million to the hospital that now bears their name, the couple announced a $120 million gift Monday to help it establish the Rady Pediatric Genomics and Systems Medicine Institute.

The latest move pushes Rady significantly further into the promising frontier of personalized medicine, which uses knowledge gleaned from a patient’s genetic code to guide treatment with unprecedented precision. The donation, combined with $40 million pledged by the hospital itself, will be used to recruit a team of physician scientists, data-analysis specialists and others to bring new therapies to the tens of thousands of young patients Rady sees every year.

In the process of providing treatment, experts plan to collaborate on research and push forward the limits of genetic understanding.

Ernest Rady, a La Jolla businessman, said the combination of treatment and research was what drew his interest.

“Children are an underserved community as far as research goes,” Rady said. “They’re a smaller market segment. They’re overlooked.”

But it’s hard to overlook the emphasis the Radys’ gift puts on pediatric genomics. Dr. Donald Kearns, the hospital’s president, said the infusion of cash will allow the institution to attract top-level scientists. The first step is to find a director for the newly minted organization, he added.

“We’ve got somebody we’re incredibly excited about who is going to be coming out for a second visit soon,” Kearns said.

Meanwhile, an old friend of Rady’s sees parallels between the current venture and the facilities expansion that occurred after the Radys’ last major donation in 2006. That contribution allowed the hospital to build out its infrastructure, adding patient rooms, operating rooms and space for outpatient services.

“Ernest is a visionary first and foremost, and he’s always looking at new possibilities. It doesn’t surprise me at all that he sees the promise of the genetics revolution,” said Blair Sadler, the hospital’s chief executive from 1980 to 2006.

With San Diego’s Illumina announcing in January that it was rolling out machines that can sequence a person’s genome for less than $1,000, the revolution is looking ever more likely. Already, doctors are starting to look to genomics when treating rare or difficult-to-diagnose diseases.

Two Rady hospital patients were early examples of this trend.

Alexis and Noah Beery of Encinitas, who attended a ceremony at the hospital’s headquarters in Serra Mesa where the $120 million donation was announced, are among the first in the nation to benefit from genetic therapies. Both suffered from movement disorders that kept getting worse. Genetic sequencing eventually revealed the source of the disorder, and a change in medication made the symptoms go away.

Pediatric genomics is a growing endeavor. Scientists at children’s hospitals in Philadelphia, Boston, Cincinnati and Texas are among those focusing on the role that genes play in many childhood diseases.

Dr. John Connolly, a neuropsychologist with the Center for Applied Genomics at Children’s Hospital of Philadelphia, explained that genetics is not simply about comprehending the intricate workings of the human genome, but also about how that code works with each person’s environment.